Detecting nucleic acids specific to an organism in an accurate and efficient way can be invaluable for identifying microbes, viruses, and other infection agents. Detecting specific proteins and nucleic acids can also be a way to detect and track the progression of diseases.
Solid-state nanopores provide a simple nucleic acid sensor. Nanopore devices can in principle be made inexpensively and incorporated into small form factors for portable and disposable use. Solid-state nanopores detect molecules by applying a voltage across the pore, and measuring ionic current flow the through pore. The current impedance changes when individual molecules pass through the nanopore, and these are referred to “events.” The overall efficacy of any given nanopore device depends on its ability to accurately and reliably measure impedance events above noise, and to discriminate events that are due to molecules of interest from events due to any background molecules when present.
Experiments published in the literature have demonstrated the detection of DNA, RNA and proteins that pass one at a time through a nanopore. Typically, a nanopore is formed in an insulating membrane by drilling with an electron or ion beam, or etching, or by the action of high voltages for controlled dielectric breakdown. Such nanopore devices that include the membrane and nanopore and inserted into a separate fluidic cell are commonly made from plastics.
The figures use like reference numerals to identify like elements. A letter after a reference numeral, such as “308a,” indicates that the text refers specifically to the element having that particular reference numeral. A reference numeral in the text without a following letter, such as “308,” refers to any or all of the elements in the figures bearing that reference numeral (e.g. “channels 308” in the text refers to reference numerals “channel 308a” and/or “channel 308b” in the figures).